The outspoken founder and 'chief unbanking officer' of FinTech start-up U has said he's determined to reach the millions of Britons with poor credit scores.

Alex Letts launched the UAccount in October 2016 to provide those underserved by retail banks with a fixed-fee, digital current account alternative and the promise of no penalty fees or hidden charges.

U has since attracted 56,000 customers, who pay a fixed fee of up to £10 per month, but Letts isn't thrilled with those figures.

"56,000 is peanuts compared to the millions and millions of people who are simply unsuited to the banks and can be helped by what we’re doing," he told BusinessCloud.

U is specifically aimed at the UK's 10 to 15 million people who have impaired credit scores that traditional banks are "desperate to get rid of" because they can't be 'monetised', Letts says.

He argues that banks are forced to provide this segment of the population with free current accounts but are unable to monetise them due to their unsatisfactory credit scores.

"The banks are losing between £100 and £125 per year on each of those customers because they give them free accounts, they can't charge them and they can't sell them any other products," he said. "Banks were never built for these people.

"The banks have been forced into a corner and made to tailor a product - the current account - that was meant for people that have lots of money and wanted to borrow more for people that are a very high credit risk, don’t have much money and may live financially chaotic lives on poor incomes."

Letts is confident that U, which is on track to turn over £3m this year and currently employs about 70 full-time and part-time staff, will be able to capture a significant portion of their target market.

"The banks aren’t doing an awful lot to stop us because they don't want these customers – they’re desperate to get rid of them," he said.

"We want to serve that underserved segment and help them get from where they are today to a place where they’ve got their finances better organised, their credit rating improved and the ability to live their lives without a continuous debt spiral and charges."

When asked about the firm's biggest challenge, Letts said it was containing his frustration and rage "that I can’t build 25 different products this week".

"It's incredibly frustrating because I know all the things we could do, should do and that our technology would let us do but it’s having all the resources and capabilities in place to deliver it all," he said.

"I see the vulnerability of the banks and I see the vulnerability of their customers and I think that we can really help these people help themselves and I’m not doing enough of it at the moment."